1. Field of the Invention
This invention relates to processes and products applicable to the human skin and more particularly to the adult human epidermis. Its object is notably a process for stimulating the growth of human epidermal cells, particularly those of adults, as well as cosmetic, pharmaceutical and diagnostic products using the said process.
2. Discussion of the Background
The skin is the principal tissue exposed to the mutagenic effects of chemical and physical environmental agents. This is particularly true of radiations of every sort. The skin is composed of tissues of mesenchymal origin (the derma and the blood vessels) and tissues of ectodermic origin (the epidermis). Although it is known to extract mesenchymal cells (fibroblasts) from the dermis to culture them and to study the mutagenic and carcinogenic effects of chemical and physical environmental factors, it is difficult to extract them from the epidermis. One of these difficulties has not yet been overcome. This is the application of processes of cytogenetic examination to cultured adult epidermal cells, which involves on the one hand the preparation and analysis of chromosomes, and on the other, the notation of sister chromatid exchanges (SCE). In point of fact, although a few rare publications mention succinct chromosomic investigations, there is no exhaustive chromosomic investigation, particularly in so far as heriditary human skin diseases are concerned and, to the best of the applicant's knowledge, no bibliographical references exist with respect to SCE.
A series of recent investigations suggests that the increase of SCEs is a sensitive and accurate indication of the mutagenic effect of a chemical product or of a radiation. The application of SCE-revealing techniques to adult human epidermal cells is, therefore, unquestionably important.